SLOT: A Soft-Legged Omnidirectional Tetrapod

Soft-legged robots are inherently more compliant to the operating environment. Rigid-legged robots require several degrees of freedom to achieve motion in all directions. This paper introduces a novel, low-cost and simple design of a soft-legged quadruped called SLOT (soft-legged omnidirectional tetrapod), which is capable of motion in all six degrees of freedom. Crawling, walking, sitting, standing, moving in longitudinal and lateral directions, turning left and right, and pitch and roll motion are achieved by only using four motors. SLOT can be operated wirelessly using Bluetooth or autonomously. Pitch, roll and height control is achieved by controlling the contraction of the legs using PID control. Handcrafted gaits are developed for crawl, turn, longitudinal, lateral and omnidirectional walk. A PID-based autonomous longitudinal control based on an ultrasonic sensor has also been demonstrated. Videos are available at https://github.com/Saumya-Karan/SLOT.